1. Chapter 29-2
Solar Activity

2. Solar Activity Gases in constant motion (rising and sinking)
Sun rotates on axis

3. Not a solid
Ball of hot gases
Close to equator – 25.3 Earth days to rotate once
Poles – 33 days
Average – 27 days

4. Sunspots Gases in convection zone + Sun’s rotation = Magnetic Field
Cause convection currents to slow in areas
Cooler areas

5. Sunspots Shine bright but less than surrounding areas Appear darker
Located in Photosphere

6. Granulation – grainy appearance of Photosphere

7. Sunspot Cycle Observation of sunspots show Sun’s rotation
11 year cycle
Start with few
Increases to 100
Then start to diminish

9. Solar Ejections Caused by change in magnetic field
Sun atomic particles
Prominences
Solar flares
Coronal mass ejections

10. Prominences Clouds of glowing gases Arch above surface
Follow curve of magnetic forces
Lasts hours to weeks

11. Solar Flares Most violent Outward eruption of charged particles
Release of energy from sunspots
Thousands of meters

12. Coronal Mass Ejection Parts of the corona that are thrown off the sun
Particles can strike Earth’s magnetosphere
Cause geomagnetic storms

14. Interfere with radio communication
Damage satellites
Blackouts

15. Auroras Interaction between solar winds and Earth’s magnetic field
Bands of light

16. Charged particles from sun hit atoms of gas in upper atmosphere
Produce sheets of light

17. Northern Lights – Aurora Borealis

18. Southern Lights – Aurora Australis

19. 100 – 1,000 km above surface
Visible in US – 4 to 5 times a year
Alaska – much more frequent
Seen from space
Jupiter and Saturn